Hydrochloric Acid → 2-Amino-3-fluorobenzoic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 19.27 g of the product of Step B and 197 ml of 10N sodium hydroxide solution was heated to 70° C. with stirring and heating was ceased to add 36.5 ml of 30% hydrogen peroxide over 20 minutes during which the temperature rose to 80° C. and descended to 70° C. At the end of the addition, the mixture was heated to 80° C. and held there for 10 minutes and then was cooled during which a mass formed. The latter was added to 200 ml of water with stirring and the pH was adjusted to 1 by addition of concentrated hydrochloric acid at a temperature less than 20° C. The mixture was stirred for 90 minutes and was vacuum filtered. The product was empasted twice with iced water and dried under reduced pressure at 70° C. The product was crystallized from 100 ml of a 1-1 ethanol-water mixture and 3 ml of acetic acid. The mixture was iced for one hour and was vacuum filtered. The product was empasted with a 1-1 ethanol-water mixture and dried at 70° C. under reduced pressure to obtain 14.8 g of 2-amino-3-fluoro-benzoic acid melting at 188° C.

Provenance & Evidence